The invention relates to a device and a method for the controlled filling of nested containers, in particular, in the pharmaceutical field.
The invention relates to a device and a method for the controlled filling of nested containers, in particular, in the pharmaceutical field.
The term “containers” is to be construed as implying vessels that are to be filled with, for example, liquids, in particular, pharmaceuticals. Included thereunder are syringes, vials, capsules, etc. The term “nested containers” is to be construed as implying containers that have been arranged in a nest or rack for further processing. Preferably involved are disposable syringes that are supplied nested and sterily packed in a box for further processing.
The proper operation of filling stations must be checked at regular intervals by measuring, or weighing, the contents of a container. That checking is also termed “in-process process control.” Such checking may be conducted at regular or irregular intervals, since it may be presumed that any changes in filling accuracy will occur relatively gradually. However, every container may also be individually checked.
In cases where individual containers are to be filled, weighing them prior to their being filled and reweighed after having been filled is presently known. The second weighing must take place before the container is sealed, since the plugs with which containers are sealed may have relatively large tolerances. That sort of checking will be sufficient when filling individual containers, since conclusions regarding the operation of the filling station involved may be drawn.
A device for weighing pharmaceutical vessels, in particular, ampoules, is known (cf. DE-U 29923418). However, on that device, vessels are conveyed, one after the other, on a transport rack, rather than being nested. A gripping device grasps several vessels from beneath the filling station and withdraws them sideward. That sort of processing is inapplicable to nested containers.
However, in the case of nested containers, several containers are simultaneously filled, which means that no conclusions regarding proper operation of a filling station may be drawn. Moreover, in the pharmaceutical field, sealing containers as soon as practicable after filling is either desirable, or demanded by regulations.
The usual practice employed to date when continuously monitoring nested containers has been manually removing several containers, extracting their contents, and measuring their contents, which requires substantial amounts of manual labor and invariably yields inaccurate results. Moreover, the extracted product is wasted. In the case of pharmaceutical products, the products involved might be very expensive.
The invention is based on the problem of devising means for conducting in-process process controls that are to be automatically conducted and capable of yielding conclusions regarding the proper operation of the filling station employed, even when filling nested containers.